Gas insulated switchgear

ABSTRACT

Each integral unit is structured by arranging partial units (I), (II), and (Ill) side by side, while line-side devices are branched from positions between the partial units adjacent to each other. Each of the partial units is structured by connecting a current transformer and a disconnector in sequence to each of upper and lower outlets horizontally drawn out from a lateral face of a vertical-type circuit breaker in the same direction. Any two partial units positioned adjacent to each other are connected in series by connecting the disconnectors included therein with a connection bus. The line-side devices are positioned to oppose the circuit breakers while the disconnectors are interposed therebetween. The switchgear includes a plurality of integral units. Two ends of each of the integral units are respectively connected to two main buses that are provided in an upper position and a lower position while the disconnectors are interposed therebetween.

TECHNICAL FIELD

The present invention relates to 1½-Circuit-Breaker(CB)-type gasinsulated switchgear.

BACKGROUND ART

Gas insulated switchgear used in electricity supply stations includingsubstations and electric power plants is structured by disposingnecessary devices such as switching devices, buses, currenttransformers, disconnectors, and voltage transformers, into a metalenclosure. The enclosure is hermetically closed after being filled witharc extinguishing gas such as sulfur hexafluoride (SF₆) having excellentinsulating and arc extinguishing properties. As a circuit type for gasinsulated switchgear, a bus connection type using a so-called1½-Circuit-Breaker (CB) configuration is sometimes used in the casewhere it is necessary to have high reliability in, for example,substations having a large capacity. According to this type of busconnections, three circuit breakers having unit configurations areconnected together in series between two main buses. In other words, thethree circuit breakers are used for drawing out two lines inconsideration that the system should not be affected even if an accidenthas occurred in any of the buses and that the lines should not have tobe stopped when the circuit breakers and the like need to be inspected.

As an example of a conventional technique that uses such a 1½-CB method,a piece of gas insulated switchgear is disclosed in, for example, PatentDocument 1. In the example disclosed in Patent Document 1, three partialunits are arranged side by side. Each of the partial units is structuredby horizontally drawing out a current transformer and a disconnector inthe same direction from a lateral face of a vertical-type circuitbreaker while arranging one above the other with an intervaltherebetween. With regard to any two partial units that are positionedadjacent to each other, the lower disconnector included in one of thetwo partial units is connected to the upper disconnector included in theother of the two partial units by using a diagonal bus, so that thethree partial units are connected together in series.

As another example, Patent Document 2 discloses an arrangement in whichthree partial units are arranged side by side. Each of the partial unitsis structured by horizontally drawing out a current transformer and adisconnector in the same direction from a lateral face of avertical-type circuit breaker while arranging one above the other withan interval therebetween. On the drawn-out side of the devices, two mainbuses are provided so as to extend at substantially the same level in alower layer below the disconnectors.

Patent Document 1: Japanese Patent Application Laid-open No. H6-62513

Patent Document 2: Japanese Patent Application Laid-open No. 11-341627

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

In the gas insulated switchgear disclosed in Patent Document 1, however,it is necessary to use the diagonal bus to connect the partial unitstogether. Thus, a problem arises where the required space increases,which leads to an increase in the costs. In addition, because of the bus(i.e., the diagonal bus) that connects the partial units together, it isdifficult to reach the disconnectors, and the convenience duringmaintenance and inspection processes performed on the disconnectors ishampered. As a result, problems arise where it becomes necessary tosecure an extra space for the maintenance and inspection processes andwhere the dimension between the partial units or the length of each ofthe partial units increases.

In the gas insulated switchgear disclosed in Patent Document 2, the twomain buses are provided below the disconnectors so as to extend atsubstantially the same level. Thus, the convenience during maintenanceand inspection processes performed on the disconnectors is hampered. Asa result, problems arise where it becomes necessary to secure an extraspace for the maintenance and inspection processes and where thedimension between the partial units or the length of each of the partialunits increases.

As explained above, both of the conventional techniques have the problemwhere the installation space increases.

The present invention has been made in view of the above, and an objectof the present invention is to provide gas insulated switchgear withwhich it is possible to secure the convenience during maintenance andinspection processes and to reduce the installation space.

Means for Solving Problem

To solve the problem described above and achieve the object, a gasinsulated switchgear according to the present invention includes aplurality of integral units, in each of which a first partial unit, asecond partial unit, and a third partial unit are connected in series insequence while line-side devices are branched from a position betweenthe first partial unit and the second partial unit and from a positionbetween the second partial unit and the third partial unit, each of thefirst, the second, and the third partial units including: a circuitbreaker of a vertical type having two branch outlets formed of upper andlower branch outlets that horizontally branch from a lateral face of thecircuit breaker in a same direction; a current transformer and an upperdisconnector that are connected in sequence to the upper branch outlet;and another current transformer and a lower disconnector that areconnected in sequence to the lower branch outlet, one end of each of theintegral units being connected to an upper main bus, whereas other endof each of the integral units being connected to a lower main bus, theupper and lower main buses being provided in an upper position and alower position, respectively, wherein the first, the second, and thethird partial units are arranged in an arranged direction side by sidesuch that heights of the circuit breakers are equal to one another andthat the two branch outlets therein are oriented in a same direction,

the lower disconnector included in the second partial unit and the lowerdisconnector included in the first or the third partial unit are at asame height and are connected by a connection bus, whereas the upperdisconnector included in the second partial unit and the upperdisconnector included in the first or the third partial unit, which isnot connected to the lower disconnector included in the second partialunit, are at a same height and are connected by a connection bus,

the upper and lower disconnectors in each of the first, the second, andthe third partial units are interposed between the upper and lower mainbuses extending in the arranging direction, the upper disconnectorincluded in the first or the third partial unit that is connected to thelower disconnector included in the second partial unit is connected tothe upper main bus via a T-shaped branch structure provided on the uppermain bus, and the lower disconnector included in the first or the thirdpartial unit that is connected to the upper disconnector included in thesecond partial unit is connected to the lower main bus via a T-shapedbranch structure provided on the lower main bus.

Effect of the Invention

According to an aspect of the present invention, with regard to theplurality of integral units each of which includes the first partialunit, the second partial unit, and the third partial unit, the partialunits are arranged side by side in such a manner that theheight-direction positions of the circuit breakers included therein areequal to one another, while the two branch outlets included therein areall oriented in the same direction. Further, the line-side devices areprovided so as to oppose the circuit breakers while the disconnectorsare interposed therebetween. Thus, the devices are gathered on the frontand the rear faces of the partial units. In other words, the circuitbreakers are principally positioned on the front face side of thepartial units, whereas the line-side devices are principally positionedon the rear face side of the partial units. As a result, it is possibleto easily reach the devices including these elements, and theconfiguration naturally makes it possible to secure the space that isrequired by the maintenance and inspection processes. Consequently,there is no need to separately provide the space used for performing themaintenance and inspection processes on the devices. Thus, it ispossible to reduce the installation space.

In addition, according to an aspect of the present invention, becausethe partial units are arranged side by side, it is possible to reducethe dimension between the partial units and the dimension in thelengthwise direction of the partial units. As a result, it is possibleto integrate the layout of the entire electricity supply station inwhich the gas insulated switchgear is installed. An advantageous effectis therefore achieved where it is possible to save space easily.

Further, according to an aspect of the present invention, thevertical-type circuit breakers each having the two branch outlets thatare provided while arranging one above the other with an intervaltherebetween are used, so that a current transformer and a disconnectorare connected in series to each of the two branch outlets. Because ofsuch a structure of each of the circuit breakers, there is no need toprovide, on the inside of each of the circuit breakers, a foldedstructure of conductors or the like, and it is therefore possible tosimplify the structure used for guiding the conductors. Thus, it ispossible to reduce the diameter of the circuit breakers. As a result, itis possible to shorten the intervals between the units and to furtherreduce the installation space.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of an example of a positional arrangement of1½-CB-type gas insulated switchgear according to a first embodiment ofthe present invention.

FIG. 2 is a top view corresponding to FIG. 1.

FIG. 3 is a cross-sectional view of a device configuration including apartial unit (I) included in the gas insulated switchgear according tothe first embodiment and is a cross-sectional view at the line A-A inFIG. 1.

FIG. 4 is a cross-sectional view of a device configuration including apartial unit (II) included in the gas insulated switchgear according tothe first embodiment and is a cross-sectional view at the line B-B inFIG. 1.

FIG. 5 is a cross-sectional view of a device configuration including apartial unit (III) included in the gas insulated switchgear according tothe first embodiment and is a cross-sectional view at the line C-C inFIG. 1.

FIG. 6 is a cross-sectional view of another positional arrangement of acircuit breaker and an operating device therefor.

FIG. 7 is a single-line wiring diagram according to the firstembodiment, a second embodiment, and a third embodiment of the presentinvention.

FIG. 8 is a front view of an example of a positional arrangement of1½-CB-type gas insulated switchgear according to the second embodiment.

FIG. 9 is a top view corresponding to FIG. 8.

FIG. 10 is a cross-sectional view of a device configuration including apartial unit (I) included in the gas insulated switchgear according tothe second embodiment and is a cross-sectional view at the line A-A inFIG. 8.

FIG. 11 is a cross-sectional view of a device configuration including apartial unit (II) included in the gas insulated switchgear according tothe second embodiment and is a cross-sectional view at the line B-B inFIG. 8.

FIG. 12 is a cross-sectional view of a device configuration including apartial unit (III) included in the gas insulated switchgear according tothe second embodiment and is a cross-sectional view at the line C-C inFIG. 8.

FIG. 13 is a front view of an example of a positional arrangement of1½-CB-type gas insulated switchgear according to the third embodiment.

FIG. 14 is a top view corresponding to FIG. 13.

FIG. 15 is a cross-sectional view of a device configuration including apartial unit (I) included in the gas insulated switchgear according tothe third embodiment and is a cross-sectional view at the line A-A inFIG. 13.

FIG. 16 is a cross-sectional view of a device configuration including apartial unit (II) included in the gas insulated switchgear according tothe third embodiment and is a cross-sectional view at the line B-B inFIG. 13.

FIG. 17 is a cross-sectional view of a device configuration including apartial unit (III) included in the gas insulated switchgear according tothe third embodiment and is a cross-sectional view at the line C-C inFIG. 13.

EXPLANATIONS OF LETTERS OR NUMERALS

1, 51, 71: Circuit breaker

2, 6, 18, 20, 23, 28, 29, 35, 43, 44: Operating device

52, 58, 62, 70, 72, 78, 82, 88, 89, 91, 92, 97: Operating device

3, 7, 53, 54, 74, 75: Branch outlet

4, 8, 55, 59, 76, 79: Current transformer

5, 9, 21, 30, 40, 41, 56, 60, 77, 80: Disconnector

10, 22, 42, 45, 61, 81: Connection bus

11, 63: Upper main bus

12, 64: Lower main bus

13, 24, 66, 84: Cable head

14, 25, 67, 85: Line-side disconnector

15, 26, 68, 86: Voltage transformer

16, 27, 69, 87: Earth switch

17, 36, 65, 73, 83: Supporting base

48, 49, 57, 98: Connection terminal

100: Installation surface

BEST MODE(S) FOR CARRYING OUT THE INVENTION

In the following sections, exemplary embodiments of gas insulatedswitchgear according to the present invention will be explained indetail, with reference to the accompanying drawings. The presentinvention is not limited to these exemplary embodiments.

First Embodiment

FIG. 1 is a front view of an example of a positional arrangement of1½-Circuit-Breaker(CB)-type gas insulated switchgear according to afirst embodiment of the present invention. FIG. 2 is a top viewcorresponding to FIG. 1. FIG. 3 is a cross-sectional view of a deviceconfiguration including a partial unit (I) included in the gas insulatedswitchgear according to the first embodiment and is a cross-sectionalview at the line A-A in FIG. 1. FIG. 4 is a cross-sectional view of adevice configuration including a partial unit (II) included in the gasinsulated switchgear according to the first embodiment and is across-sectional view at the line B-B in FIG. 1. FIG. 5 is across-sectional view of a device configuration including a partial unit(III) included in the gas insulated switchgear according to the firstembodiment and is a cross-sectional view at the line C-C in FIG. 1. FIG.6 is a cross-sectional view of another positional arrangement of acircuit breaker and an operating device therefor. FIG. 7 is asingle-line wiring diagram according to the first embodiment.

The 1½-CB-type gas insulated switchgear according to the firstembodiment is configured so as to include a plurality of integral units.Each of the integral units is structured by connecting partial units(I), (II), and (III) together in series, while line-side devices areconfigured so as to branch from a connection line that connects thepartial units (I) and (II) together and from a connection line thatconnects the partial units (II) and (III) together. Each of the partialunits (I), (II), and (III) is structured by connecting a currenttransformer for instruments (hereinafter, “current transformer”) and adisconnector with an earth switch in sequence to both sides of eachcircuit breaker. With regard to two main buses, one end of each of theintegral units is connected to one of the two main buses, whereas theother end of each of the integral units is connected to the other of thetwo main buses.

The connection mode described above will be explained in detail, withreference to the single-line wiring diagram in FIG. 7. As shown in FIG.7, each of the partial units (I) is configured so as to include acurrent transformer (CT) and a disconnector with an earth switch (DS/ES)on each of the two sides of the circuit breaker (CB). The sameconfiguration applies to each of the partial units (II) and the partialunits (III). The partial units (I), (II), and (III) are connectedtogether in series in the stated order. A branch line is drawn from aconnection line that connects the partial units (I) and (II) togetherand another branch line is drawn from a connection line that connectsthe partial units (II) and (III) together. Line-side devices including aline-side disconnector with an earth switch (LINE-DS/ES), a voltagetransformer for instruments (hereinafter, “voltage transformer”) (VT),an earth switch for a line-side earth (ES) and a cable head (CHD) areconnected to each of the branch lines. An integral unit is structuredwith the partial units (I), (II), and (III) and the line-side devicesthat are connected so as to branch from the positions between thepartial units. In the example shown in FIG. 7, two integral units areprovided. The partial units (I) and (III) that are respectivelypositioned on the both ends of each of the integral units. Of the twodisconnectors (DS/ES) included in the partial unit (I), the disconnector(DS/ES) that is not connected to the partial unit (II) is connected to alower main bus, which is one of the two main buses. Of the twodisconnectors (DS/ES) included in the partial unit (III), thedisconnector (DS/ES) that is not connected to the partial unit (II) isconnected to an upper main bus. In the description of the firstembodiment, an example in which the number of integral units is two willbe explained; however, the present invention is not limited to thisexample. The number of integral units may be three or more.

Next, configurations of the devices including configurations of thepartial units (I), (II), and (III) will be explained in detail, withreference to FIGS. 3 to 5. After that, an overall layout will beexplained, with reference to FIGS. 1 and 2.

First, a configuration of the devices including the partial unit (I)will be explained. As shown in FIG. 3, a circuit breaker 1 that iscircular cylindrical shaped and has an operating device 2 thereforunderneath is provided so as to stand in such a manner that the axialline thereof extends perpendicular to an installation surface 100. Inother words, the circuit breaker 1 is a vertical-type circuit breaker. Acircuit breaking unit (not shown) is provided on the inside of thecircuit breaker 1, which is a space filled with insulating and arcextinguishing gas such as SF₆.

On a lateral face of the circuit breaker 1, two branch outlets areprovided while arranging one above the other with an intervaltherebetween, the two branch outlets namely being a branch outlet 3provided in a lower position and a branch outlet 7 provided in an upperposition. The branch outlets 3 and 7 are horizontally drawn out so as tobranch from the lateral face of the circuit breaker 1 in the samedirection.

A current transformer 4 and a disconnector 5 with an earth switch areconnected to the branch outlet 3 in series in the stated order. Anoperating device 6 for operating the disconnector 5 is provided on alateral face of the disconnector 5. A lower main bus 12, which is thelower one of two main buses that extend along each other while arrangingone above the other with an interval therebetween, is provided below thedisconnector 5. The disconnector 5 is connected to the lower main bus 12via a branch portion 32. The branch portion 32 is a T-shaped branchstructure that branches from the lower main bus 12.

A current transformer 8 and a disconnector 9 with an earth switch areconnected to the branch outlet 7 in series in the stated order. Aconnection bus 10 extending in a direction that is orthogonal to thecircuit breaker 1 and the current transformers 4 and 8 is connected tothe disconnector 9. The connection bus 10 connects together the partialunit (I) and the partial unit (II), which is positioned adjacent to thepartial unit (I). An operating device 18 for operating the disconnector9 is provided on top of the disconnector 9.

An upper main bus 11, which is the upper one of the two main busesdescribed above, is provided above the disconnector 9. The upper mainbus 10 and the lower main bus 12 are provided so as to extendhorizontally and parallel to each other. The direction in which theconnection bus 11 extends is the same as the direction in which theupper main bus 11 and the lower main bus 12 extend.

Opposing the circuit breaker 1 while the disconnectors 5 and 9 areinterposed therebetween, a cable head 13 is provided on a supportingbase 17, a line-side disconnector 14 with an earth switch is connectedon top of the cable head 13, an operating device 19 for the line-sidedisconnector 14 is provided on a lateral face of the line-sidedisconnector 14, and a voltage transformer 15 is provided on top of theline-side disconnector 14. Also, while being connected to the line-sidedisconnector 14, an earth switch 16 for a line-side earth is provided onanother lateral face of the line-side disconnector 14 that is positionedon the opposite side from the circuit breaker 1. In addition, anoperating device 20 for operating the earth switch 16 is provided.Further, the line-side disconnector 14 is connected to the disconnector9, which is connected to the circuit breaker 1. The portion of thedisconnector 9 connected to the disconnector 14 is positioned on theopposite side from the current transformer 8 so as to oppose theconnection portion at which the disconnector 9 is connected to thecurrent transformer 8. In other words, the disconnector 9 has a T-shapedbranch structure in which a branch portion to which the currenttransformer 8 is connected and another branch portion to which theline-side disconnector 14 is connected are positioned so as to opposeeach other, while the connection bus 10 is connected to the other branchportion that is orthogonal to these opposing branches.

A path that extends from the disconnector 9 to the cable head 13 changesdirection by 90 degrees at the line-side disconnector 14, so that thepath substantially forms an L shape. In other words, the line-sidedisconnector 14 is horizontally connected to the disconnector 9, whilethe cable head 13 is connected underneath the line-side disconnector 14so as to extend downward. Thus, the path that extends from thedisconnector 9 to the cable head 13 looks like an L that is inverted inthe right-and-left direction and rotated counterclockwise by 90 degrees.

As explained above, the partial unit (I) includes the vertical-typecircuit breaker 1 provided with the branch outlets 3 and 7, the currenttransformers 4 and 8, and the disconnectors 5 and 9 each provided withan earth switch. Further, the line-side devices such as the cable head13, the line-side disconnector 14, and the voltage transformer 15 areconnected so as to oppose the circuit breaker 1 while the disconnectors5 and 9 are interposed therebetween.

Next, configurations of the devices including the partial unit (II) willbe explained. Some of the constituent elements that are the same asthose in the partial unit (I) will be referred to by using the samereference characters. As shown in FIG. 4, the positional arrangement ofthe vertical-type circuit breaker 1, the operating device 2 for thecircuit breaker 1, the branch outlets 3 and 7 provided on a lateral faceof the circuit breaker 1, the current transformer 4 connected to thebranch outlet 3, and the current transformer 8 connected to the branchoutlet 7 is the same as that in the partial unit (I).

A disconnector 21 with an earth switch is connected to the currenttransformer 4. In other words, the current transformer 4 and thedisconnector 21 with an earth switch are connected to the circuitbreaker 1 in series via the branch outlet 3 in sequence. An operatingdevice 23 for operating the disconnector 21 is provided on top of thedisconnector 21. Further, a connection bus 22 is connected to thedisconnector 21 while extending in a direction that is orthogonal to thecircuit breaker 1 and the current transformers 4 and 8. The connectionbus 22 connects the partial unit (II) and the partial unit (III)together.

A disconnector 9 with an earth switch is connected to the currenttransformer 8. In other words, like in the partial unit (I), the currenttransformer 8 and the disconnector 9 with an earth switch are connectedto the circuit breaker 1 in series via the branch outlet 7 in sequence.The operating device 18 is provided on top of the disconnector 9.Further, as described above, the connection bus 10 that connects thepartial unit (I) and the partial unit (II) together is connected to thedisconnector 9.

The upper main bus 11 is positioned above the disconnector 9, whereasthe lower main bus 12 is positioned below the disconnector 21. Theconnection bus 22 extends parallel to the upper main bus 11 and to thelower main bus 12. The connection bus 22 and the connection bus 10extend in opposite directions.

Opposing the circuit breaker 1 while the disconnectors 9 and 21 eachprovided with an earth switch are interposed therebetween, a cable head24 is provided on the installation surface 100, a line-side disconnector25 with an earth switch is connected on top of the cable head 24, anoperating device 29 for the line-side disconnector 25 is provided on alateral face of the line-side disconnector 25, and a voltage transformer26 is provided on top of the line-side disconnector 25. Also, whilebeing connected to the line-side disconnector 25, an earth switch 27 fora line-side earth is provided on another lateral face of the line-sidedisconnector 25 that is positioned on the opposite side from the circuitbreaker 1. In addition, an operating device 28 for operating the earthswitch 27 is provided. Further, the line-side disconnector 25 isconnected to the disconnector 21, which is connected to the circuitbreaker 1. The portion of the disconnector 21 connected to thedisconnector 25 is positioned on the opposite side from the currenttransformer 4 so as to oppose the connection portion at which thedisconnector 21 is connected to the current transformer 4. In otherwords, the disconnector 21 has a T-shaped branch structure in which abranch portion to which the current transformer 4 is connected andanother branch portion to which the line-side disconnector 25 isconnected are positioned so as to oppose each other, while theconnection bus 22 is connected to the branch portion that is orthogonalto these opposing branches. As explained, the disconnector 21 branchesin the shape of a T on a horizontal plane, which is positioned parallelto the installation surface 100.

A path that extends from the disconnector 21 to the cable head 24changes direction by 90 degrees at the line-side disconnector 25, sothat the path substantially forms an L shape. In other words, theline-side disconnector 25 is horizontally connected to the disconnector21, while the cable head 24 is connected underneath the line-sidedisconnector 25 so as to extend downward. Thus, the path that extendsfrom the disconnector 21 to the cable head 24 looks like an L that isinverted in the right-and-left direction and rotated counterclockwise by90 degrees.

As explained above, the partial unit (II) includes the vertical-typecircuit breaker 1 provided with the branch outlets 3 and 7, the currenttransformers 4 and 8, and the disconnectors 21 and 9 each provided withan earth switch. Further, the line-side devices such as the cable head24, the line-side disconnector 25, and the voltage transformer 26 areconnected so as to oppose the circuit breaker 1 while the disconnectors21 and 9 are interposed therebetween.

Next, configurations of the devices including the partial unit (III)will be explained. Some of the constituent elements that are the same asthose in the partial units (I) and (II) will be referred to by using thesame reference characters. As shown in FIG. 5, the positionalarrangement of the vertical-type circuit breaker 1, the operating device2 for the circuit breaker 1, the branch outlets 3 and 7 provided on alateral face of the circuit breaker 1, the current transformer 4connected to the branch outlet 3, and the current transformer 8connected to the branch outlet 7 is the same as that in the partialunits (I) and (II).

The disconnector 21 with an earth switch is connected to the currenttransformer 4. In other words, like in the partial unit (II), thecurrent transformer 4 and the disconnector 21 with an earth switch areconnected to the circuit breaker 1 in series via the branch outlet 3 insequence. The operating device 23 for operating the disconnector 21 isprovided on top of the disconnector 21. Further, the connection bus 22is connected to the disconnector 21 while extending in a direction thatis orthogonal to the circuit breaker 1 and the current transformers 4and 8. As described above, the connection bus 22 connects the partialunit (II) and the partial unit (III) together.

The current transformer 8 and a disconnector 30 with an earth switch areconnected, in series and in sequence, to the branch outlet 7, which isthe upper branch outlet provided on the circuit breaker 1. The uppermain bus 11 is positioned above the disconnector 30, whereas the lowermain bus 12 is positioned below the disconnector 21. An operating device91 for operating the disconnector 30 is provided on a lateral face ofthe disconnector 30. The disconnector 30 is connected to the upper mainbus 11 via a branch portion 31. The branch portion 31 is a branchportion having a T-shaped branch structure that branches from the uppermain bus 11. It should be noted that no line-side devices are providedso as to oppose the partial unit (III).

Next, a layout according to the first embodiment will be explained indetail, with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, inthe 1½-CB-type gas insulated switchgear according to the firstembodiment, for example, two integral units are arranged side by side.Each of the integral units includes the partial unit (I), the partialunit (II), and the partial unit (III). Further, throughout both of thetwo integral units, the intervals between two partial units areconfigured so as to be regular intervals each of which can be expressedas W. In the example shown in FIGS. 1 and 2, the partial units arearranged in the following order from the left-hand side to theright-hand side of the drawings: the partial unit (I), the partial unit(II), and the partial unit (III); however, needless to say, it ispossible to arrange the partial units in the reverse order.

The partial units (I), (II), and (III) are arranged so as to be parallelto one another in such a manner that the branch outlets 3 and 7 of thecircuit breakers 1 are all oriented in the same direction and that theheight-direction positions of the circuit breakers 1 are equal to oneanother. The direction in which the partial units (I), (II), and (III)are arranged is a direction that is orthogonal to the branchingdirection of the branch outlets 3 and 7, i.e., a direction that isorthogonal to the circuit breaker 1 and the current transformers 4 and8. In other words, the circuit breakers 1 and the current transformers 4and 8 included in the partial units are arranged side by side so as tobe parallel to one another. Accordingly, between the two integral units,the height-direction positions of the upper disconnectors connected tothe respective circuit breakers 1 are equal to one another. Similarly,between the two integral units, the height-direction positions of thelower disconnectors connected to the respective circuit breakers 1 areequal to one another.

In the following sections, to explain the mode of connection used forconnecting the partial units together, the connections between thepartial units will be explained from the left-hand side to theright-hand side of the drawings, while referring to FIGS. 1 and 2.First, the partial unit (I) is connected to the partial unit (II) thatis positioned adjacent to the partial unit (I) by the connection bus 10.More specifically, the disconnector 9 included in the partial unit (I)is connected to the disconnector 9 included in the partial unit (II) bythe connection bus 10. As explained above, each of the disconnectors 9is a disconnector that is connected to the upper branch outlet 7 of thecorresponding one of the circuit breakers 1. Accordingly, by connectingthe upper disconnectors 9 to each other with the connection bus 10, thepartial unit (I) is connected to the partial unit (II), which ispositioned adjacent to the partial unit (I).

Further, the partial unit (II) is connected to the partial unit (III),which is positioned adjacent to the partial unit (II) on the right-handside thereof, by the connection bus 22. More specifically, thedisconnector 21 included in the partial unit (II) is connected to thedisconnector 21 included in the partial unit (III) by the connection bus22. As explained above, each of the disconnectors 21 is a disconnectorthat is connected to the lower branch outlet 3 of the corresponding oneof the circuit breakers 1. Accordingly, by connecting the lowerdisconnectors 21 to each other with the connection bus 22, the partialunit (II) is connected to the partial unit (III), which is positionedadjacent to the partial unit (II) on the right-hand side thereof.

The mode of connection between the partial units described above isapplied both of the integral units. In other words, the connection bus10 that connects the upper disconnectors 9 to each other is used for theconnection between the partial unit (I) and the partial unit (II). Theconnection bus 22 that connects the lower disconnectors 21 to each otheris used for the connection between the partial unit (II) and the partialunit (III). The connection buses 10 and the connection buses 22 arearranged alternately along the direction in which the partial units arearranged. The connection buses 10 are provided in positions that arehigher than the positions in which the connection buses 22 are provided.In other words, the connection buses are provided alternately between anupper position and a lower position along the direction in which thepartial units are arranged. As a result, the positions of the bus pathsconnecting the partial units to one another also change between theupper positions and the lower positions.

The upper main bus 11 and the lower main bus 12 are provided so as toextend in the direction in which the partial units are arranged side byside, while the disconnectors 5, 9, 21, and 30 are interposedtherebetween. The disconnector 5 included in the partial unit (I), whichis positioned on the left-hand-side end of each of the integral units,is connected to the lower main bus 12 via the branch portion 32 thatbranches from the lower main bus 12 in the shape of a T. Further, thedisconnector 30 included in the partial unit (III), which is positionedon the right-hand-side end of each of the integral units, is connectedto the upper main bus 11 via the branch portion 31 that branches fromthe upper main bus 11 in the shape of a T. By using the T-shaped branchstructures of the disconnectors 5 and 30, the height levels of thebranch portions to the line-side devices are configured so as to bedifferent from the height levels of the main bus connection portions. Asa result, it is possible to arrange the two main buses linearly.

With regard to the partial unit (I), the line-side devices are providedso as to oppose the circuit breaker 1 while the disconnectors 5 and 9are interposed therebetween. The same positional arrangement alsoapplies to the partial unit (II). Accordingly, due to the 1½-CB-typeconfiguration, no line-side devices are provided for the partial unit(III). In other words, one set of line-side devices is connected to eachof the disconnectors included in two of the partial units (I), (II), and(III), while opposing the current-transformer-side connection face.Further, throughout the plurality of integral units, the partial unitsto which no line-side devices are connected are arranged at regularintervals in the direction in which the partial units are arranged. Forexample, in the example shown in FIG. 2, no line-side devices areconnected to the partial units (III) in both of the two integral units.

According to the first embodiment, with regard to the plurality ofintegral units each of which includes the partial units (I), (II), and(III), the two branch outlets 3 and 7 of the circuit breakers 1 includedin the partial units are all oriented in the same direction, while thepartial units are linearly arranged in the direction that is orthogonalto the orientation direction. Further, the line-side devices areprovided so as to oppose the circuit breakers 1 while the disconnectorsare interposed therebetween. Thus, the devices are gathered on the frontand the rear faces of the partial units. In other words, the circuitbreakers 1 are principally positioned on the front face side of thepartial units, whereas the line-side devices are principally positionedon the rear face side of the partial units. As a result, it is possibleto easily reach the devices including these elements, and theconfiguration naturally makes it possible to secure the space that isrequired by the maintenance and inspection processes. For example, inFIG. 2, there is no need to provide the space used for performingmaintenance and inspection processes on the circuit breaker 1 and theearth switches 16 and 27. It is possible to easily reach the operatingdevices for operating these devices. As explained, according to thefirst embodiment, because the devices are gathered on the front and therear faces of the partial units, there is no need to provide anotherspace used for performing the maintenance and inspection processes onthe devices. Thus, it is possible to reduce the installation space.

In addition, according to the first embodiment, because the partialunits are arranged side by side, it is possible to reduce the dimensionbetween the partial units and the dimension in the lengthwise directionof the partial units. As a result, it is possible to integrate thelayout of the entire electricity supply station in which the gasinsulated switchgear is installed. An advantageous effect is thereforeachieved where it is possible to save space easily. This arrangement iseffective especially when cable connections are used on the line side.

Further, according to the first embodiment, the vertical-type circuitbreakers 1 each having the two branch outlets 3 and 7 that are providedone above the other with an interval therebetween are used, so that acurrent transformer and a disconnector are connected in series to eachof the two branch outlets. Because of such a structure of each of thecircuit breakers 1, there is no need to provide, on the inside of eachof the circuit breakers 1, a folded structure of conductors or the like,and it is therefore possible to simplify the structure used for guidingthe conductors. Thus, it is possible to reduce the diameter of thecircuit breakers. As a result, it is possible to shorten the intervalsbetween the units and to further reduce the installation space.

In addition, according to the first embodiment, the circuit breakers 1are positioned in the lower layer. Thus, it is possible to greatlyreduce the number of supporting bases. As a result, it is possible toreduce the costs and to improve quake-resistant properties.Alternatively, it is also acceptable to use a positional arrangement ofthe circuit breakers 1 as shown in FIG. 6. More specifically, in theexample shown in FIG. 6, an operating device 35 for the circuit breaker1 is provided on top of the circuit breaker 1, and the circuit breaker 1is supported by a supporting base 36. It should be noted, however, thatthe height of the supporting base 36 is adjusted in such a manner thatthe height-direction positions of the branch outlets 3 and 7 shown inFIG. 6 are the same as the height-direction positions of the branchoutlets 3 and 7 shown in FIGS. 3 to 5.

Further, according to the first embodiment, each of the disconnectors 5,9, 21, and 30 has the T-shaped branch structure. As a result, it ispossible to reduce the number of tanks and spacers used for connectingthe devices to one another. Thus, it is possible not only to reduce theinstallation space, but also to reduce the costs.

Furthermore, according to the first embodiment, one set of line-sidedevices is connected to each of the partial units. As a result, it ispossible to reduce the dimension in the lengthwise direction of thepartial units. Thus, it is possible to shorten the total length of theentire electricity supply station. Alternatively, another arrangement isalso acceptable in which, for example, two sets of line-side devices areconnected to one partial unit. As yet another arrangement, it is alsoacceptable to position the line-side devices between the partial units,by folding the structure back to the circuit breaker 1 side. Thisarrangement is suitable in a situation where the size of the line-sidedevices is large.

According to the first embodiment, one set of line-side devices isconnected to each of two of the partial units (I), (II), and (III).Further, throughout the plurality of integral units, the partial unitsto which no line-side devices are connected are arranged at regularintervals in the direction in which the partial units are arranged. Inthe example shown in FIG. 2, no line-side devices are connected to thepartial units (III) in both of the two integral units. With thisarrangement, because no line-side devices are connected to the partialunits (III), an empty space is formed in the lengthwise direction ofeach of the partial units (III). By utilizing these empty spaces (e.g.,by providing, in an integrated manner, an operation box that alsofunctions for the adjacent partial units), it is possible to easilyperform the maintenance and inspection processes not only on thedisconnectors 21 and 30 included in the partial unit (III), but also onthe disconnectors 5 and 9 included in the adjacent partial unit (I) andthe disconnectors 9 and 21 included in the adjacent partial unit (II) onthe opposite side. If such empty spaces were not positioned at regularintervals in the direction in which the partial units are arranged,there would be some disconnectors that are difficult to reach, and theconvenience during the maintenance and inspection processes would behampered. As explained, because the partial units (I), (II), and (III)and the line-side devices are arranged with high density, there is noneed to provide a space dedicated to the maintenance and inspectionprocesses. Thus, it is possible to shorten, in particular, the intervalsbetween the partial units.

According to the first embodiment, for example, the path that extendsfrom the disconnector 9 to the cable head 13 changes direction by 90degrees at the line-side disconnector 14, so that the path substantiallyforms an L shape. As a result, it is possible to reduce the dimension inthe lengthwise direction of the partial units and to shorten the totallength of the electricity supply station.

In addition, according to the first embodiment, throughout the pluralityof integral units, all the partial units are arranged at the regularintervals. As a result, it is possible to reduce the dimension betweenthe units and to shorten the width of the electricity supply station.

Further, as shown in FIG. 1, the disconnectors 5 and 30 that arepositioned on the two ends of each of the integral units are connectedto the lower main bus 12 and the upper main bus 11 via the branchportions 32 and 31, respectively. Thus, when it is necessary toadditionally provide another integral unit, connections can be made tothe end portions of the upper main bus 11 and the lower main bus 12.Thus, it is possible to provide additional integral units easily.

In the sections above, the example of a three-phase system has beenexplained; however, the present invention is not limited to thisexample. It is possible to apply the present invention likewise to anisolated phase system.

Second Embodiment

FIG. 8 is a front view of an example of a positional arrangement of1½-CB-type gas insulated switchgear according to a second embodiment ofthe present invention. FIG. 9 is a top view corresponding to FIG. 8.FIG. 10 is a cross-sectional view of a device configuration including apartial unit (I) included in the gas insulated switchgear according tothe second embodiment and is a cross-sectional view at the line A-A inFIG. 8. FIG. 11 is a cross-sectional view of a device configurationincluding a partial unit (II) included in the gas insulated switchgearaccording to the second embodiment and is a cross-sectional view at theline B-B in FIG. 8. FIG. 12 is a cross-sectional view of a deviceconfiguration including a partial unit (III) included in the gasinsulated switchgear according to the second embodiment and is across-sectional view at the line C-C in FIG. 8.

The 1½-CB-type gas insulated switchgear according to the secondembodiment is configured so as to include a plurality of integral units.Each of the integral units is structured by connecting partial units(I), (II), and (III) together in series, while line-side devices areconfigured so as to branch from a connection line that connects thepartial units (I) and (II) together and from a connection line thatconnects the partial units (II) and (III) together. Each of the partialunits (I), (II), and (III) is structured by connecting a currenttransformer and a disconnector with an earth switch in sequence to eachof the two sides of a circuit breaker With regard to two main buses, oneend of each of the integral units is connected to one of two main buses,whereas the other end of each of the integral units is connected to theother of the two main buses. Because the single-line wiring diagramaccording to the second embodiment is the same as the one shown in FIG.7, the explanation thereof will be omitted.

Next, configurations of the devices including the configurations of thepartial units (I), (II), and (III) will be explained in detail, withreference to FIGS. 10 to 12. After that, an overall layout will beexplained, with reference to FIGS. 8 and 9.

First, a configuration of the devices including the partial unit (I)will be explained. As shown in FIG. 10, the circuit breaker 1 that has acircular cylindrical shape and has the operating device 35 therefor ontop is provided so as to stand in such a manner that the axial linethereof extends perpendicular to the installation surface 100. In otherwords, the circuit breaker 1 is a vertical-type circuit breaker. Acircuit breaking unit (not shown) is provided on the inside of thecircuit breaker 1, which is a space filled with insulating and arcextinguishing gas such as SF₆.

On a lateral face of the circuit breaker 1, two branch outlets areprovided while arranging one above the other with an interval Htherebetween, the two branch outlets namely being the branch outlet 3provided in a lower position and the branch outlet 7 provided in anupper position. The branch outlets 3 and 7 are horizontally drawn out soas to branch from the lateral face of the circuit breaker 1 in the samedirection.

The current transformer 4 and a disconnector 40 with an earth switch areconnected to the branch outlet 3 in series in the stated order. Anoperating device 43 for operating the disconnector 40 is provided on topof the disconnector 40. The lower main bus 12, which is the lower one oftwo main buses that extend along each other while arranged one above theother with interval 3H therebetween, is connected to the disconnector 40via a connection terminal 48 provided for the connector 40.

The current transformer 8 and a disconnector 41 with an earth switch areconnected to the branch outlet 7 in series in the stated order. Aconnection bus 42 extending in a direction that is orthogonal to thecircuit breaker 1 and the current transformers 4 and 8 is connected tothe disconnector 41. The connection bus 42 connects together the partialunit (I) and the partial unit (II), which is positioned adjacent to thepartial unit (I). An operating device 44 for operating the disconnector41 is provided on top of the disconnector 41.

The upper main bus 11, which is the upper one of the two main busesdescribed above, is provided above the disconnector 41. The upper mainbus 11 and the lower main bus 12 are provided so as to extendhorizontally and parallel to each other. The direction in which theconnection bus 42 extends is the same as the direction in which theupper main bus 11 and the lower main bus 12 extend. As described above,the distance between the upper main bus 11 and the lower main bus 12 canbe expressed as 3H, whereas the distance between the connection bus 42and the lower main bus 12 can be expressed as H. Accordingly, thedistance between the connection bus 42 and the upper main bus 11 can beexpressed as 2H.

Opposing the circuit breaker 1 while the disconnectors 40 and 41 areinterposed therebetween, the cable head 24 is provided on theinstallation surface 100, the line-side disconnector 25 with an earthswitch is connected on top of the cable head 24, the operating device 29for the line-side disconnector 25 is provided on a lateral face of theline-side disconnector 25, and the voltage transformer 26 is provided ontop of the line-side disconnector 25. Also, while being connected to theline-side disconnector 25, the earth switch 27 for a line-side earth isprovided on another lateral face of the line-side disconnector 25 thatis positioned on the opposite side from the circuit breaker 1. Inaddition, the operating device 28 for operating the earth switch 27 isprovided. Further, the line-side disconnector 25 is connected to thedisconnector 41, which is connected to the circuit breaker 1. Theportion of the disconnector 41 connected to the line-side disconnector25 is positioned on the opposite side from the current transformer 8 soas to oppose the connection portion at which the disconnector 41 isconnected to the current transformer 8. In other words, the disconnector41 has a T-shaped branch structure in which a branch portion to whichthe current transformer 8 is connected and another branch portion towhich the line-side disconnector 25 is connected are positioned so as tooppose each other, while the connection bus 42 is connected to the otherbranch portion that is orthogonal to these opposing branches. Asexplained here, the disconnector 41 branches in the shape of a T on ahorizontal plane, which is positioned parallel to the installationsurface 100.

A path that extends from the disconnector 41 to the cable head 24changes direction by 90 degrees at the line-side disconnector 25, sothat the path substantially forms an L shape.

As explained above, the partial unit (I) includes the vertical-typecircuit breaker 1 provided with the branch outlets 3 and 7, the currenttransformers 4 and 8, and the disconnectors 40 and 41 each provided withan earth switch. Further, the line-side devices such as the cable head24, the line-side disconnector 25, and the voltage transformer 26 areconnected so as to oppose the circuit breaker 1 while the disconnectors40 and 41 are interposed therebetween.

Next, configurations of the devices including the partial unit (II) willbe explained. Some of the constituent elements that are the same asthose in the partial unit (I) will be referred to by using the samereference characters. As shown in FIG. 11, the circuit breaker 1 thathas a circular cylindrical shape and has the operating device 2 thereforunderneath is provided so as to stand in such a manner that the axialline thereof extends perpendicular to the installation surface 100. Likein the partial unit (I), to the vertical-type circuit breaker 1, thebranch outlets 3 and 7 having an interval H therebetween, the currenttransformer 4 and the disconnector 40 with an earth switch that areconnected in series to the branch outlet 3 in sequence, and the currenttransformer 8 and the disconnector 41 with an earth switch that areconnected in series to the branch outlet 7 in sequence are connected.

The connection bus 42 is connected to the disconnector 40 whileextending in a direction that is orthogonal to the circuit breaker 1 andthe current transformers 4 and 8. As explained above, the connection bus42 connects the partial unit (II) and the partial unit (I) together. Theoperating device 43 for operating the disconnector 40 is provided on topof the disconnector 40.

A connection bus 45 is connected to the disconnector 41 while extendingin a direction that is orthogonal to the circuit breaker 1 and thecurrent transformers 4 and 8. The connection bus 45 connects the partialunit (II) and the partial unit (III) together. The connection bus 45extends in a direction opposite from the direction in which theconnection bus 42 extends. The operating device 44 for operating thedisconnector 41 is provided on top of the disconnector 41.

The upper main bus 11 is positioned above the disconnector 41 whilehaving an interval H therebetween, whereas the lower main bus 12 ispositioned below the disconnector 40 while having an interval Htherebetween. The connection buses 42 and 45 extend parallel to theupper main bus 11 and the lower main bus 12.

Opposing the circuit breaker 1 while the disconnectors 40 and 41 eachprovided with an earth switch are interposed therebetween, the cablehead 13 is provided on the supporting base 17, the line-sidedisconnector 14 with an earth switch is connected on top of the cablehead 13, the operating device 19 for the line-side disconnector 14 isprovided on a lateral face of the line-side disconnector 14, and thevoltage transformer 15 is provided on top of the line-side disconnector14. Also, while being connected to the line-side disconnector 14, theearth switch 16 for a line-side earth is provided on another lateralface of the line-side disconnector 14 that is positioned on the oppositeside from the circuit breaker 1. In addition, the operating device 20for operating the earth switch 16 is provided. Further, the line-sidedisconnector 14 is connected to the disconnector 41, which is connectedto the circuit breaker 1. The portion of the disconnector 41 connectedto the disconnector 14 is positioned on the opposite side from thecurrent transformer 8 so as to oppose the connection portion at whichthe disconnector 41 is connected to the current transformer 8. In otherwords, the disconnector 41 has a T-shaped branch structure in which abranch portion to which the current transformer 8 is connected andanother branch portion to which the line-side disconnector 14 isconnected are positioned so as to oppose each other, while theconnection bus 45 is connected to the other branch portion that isorthogonal to these opposing branches. As explained here, thedisconnector 41 branches in the shape of a T on a horizontal plane,which is positioned parallel to the installation surface 100.

A path that extends from the disconnector 41 to the cable head 13changes direction by 90 degrees at the line-side disconnector 14, sothat the path substantially forms an L shape.

As explained above, the partial unit (II) includes the vertical-typecircuit breaker 1 provided with the branch outlets 3 and 7, the currenttransformers 4 and 8, and the disconnectors 40 and 41 each provided withan earth switch. Further, the line-side devices such as the cable head13, the line-side disconnector 14, and the voltage transformer 15 areconnected so as to oppose the circuit breaker 1 while the disconnectors40 and 41 are interposed therebetween.

Next, configurations of the devices including the partial unit (III)will be explained. Some of the constituent elements that are the same asthose in the partial units (I) and (II) will be referred to by using thesame reference characters. As shown in FIG. 12, the operating device 2and the vertical-type circuit breaker 1 are provided in sequence on thesupporting base 36. The operating device 2 is an operating device forthe circuit breaker 1. Like in the partial unit (II), the branch outlets3 and 7 are provided on a lateral face of the circuit breaker 1 whilehaving an interval H therebetween. The current transformer 4 and thedisconnector 40 with an earth switch are connected in series to thebranch outlet 3 in sequence, whereas the current transformer 8 and thedisconnector 41 with an earth switch are connected in series to thebranch outlet 7 in sequence.

The operating device 43 for operating the disconnector 40 is provided ontop of the disconnector 40. In addition, the connection bus 45 isconnected to the disconnector 40 while extending in a direction that isorthogonal to the circuit breaker 1 and the current transformers 4 and8. As explained above, the connection bus 45 connects the partial unit(III) and the partial unit (II) together. The lower main bus 12 isprovided below the disconnector 40. The lower main bus 12 is positionedbelow the connection bus 45 while having an interval 2H therebetween.

An operating device 44 for operating the disconnector 41 is provided ontop of the disconnector 41. Further, the upper main bus 11 is connectedto the disconnector 41 via a connection terminal 49 provided for thedisconnector 41. It should be noted that no line-side devices areprovided so as to oppose the partial unit (III).

Next, a layout according to the second embodiment will be explained indetail, with reference to FIGS. 8 and 9. As shown in FIGS. 8 and 9, inthe 1½-CB-type gas insulated switchgear according to the secondembodiment, for example, two integral units are arranged side by side.Each of the integral units includes the partial unit (I), the partialunit (II), and the partial unit (III). Further, throughout both of thetwo integral units, the intervals between two partial units areconfigured so as to be regular intervals each of which can be expressedas W.

Next, a positional relationship between the partial unit (I) and thepartial unit (II) will be explained. The partial units (I) and (II) arepositioned in such a manner that the height of the disconnector 40,which is the lower disconnector included in the partial unit (II), isequal to the height of the disconnector 41, which is the upperdisconnector included in the partial unit (I). In other words, thecircuit breaker 1 included in the partial unit (I) is installed directlyon the installation surface 100, whereas the circuit breaker 1 includedin the partial unit (II) is installed while the operating device 2 isinterposed underneath the circuit breaker 1, so that the relativeheights can be adjusted. Further, the disconnector 41 included in thepartial unit (I) and the disconnector 40 included in the partial unit(II) are connected to each other at the same height level by theconnection bus 42.

Next, a positional relationship between the partial unit (II) and thepartial unit (III) will be explained. The partial units (II) and (III)are positioned in such a manner that the height of the disconnector 41,which is the upper disconnector included in the partial unit (II), isequal to the height of the disconnector 40, which is the lowerdisconnector included in the partial unit (III). In other words, thecircuit breaker 1 included in the partial unit (II) is installed whilethe operating device 2 is interposed underneath the circuit breaker 1,whereas the circuit breaker 1 included in the partial unit (III) isinstalled on the operating device 2, which is supported by thesupporting base 36, so that the relative heights can be adjusted.Further, the disconnector 41 included in the partial unit (II) and thedisconnector 40 included in the partial unit (III) are connected to eachother at the same height level by the connection bus 45. To clearlyindicate the relative positional relationships among the partial units,in the drawing of the partial unit (III) in FIG. 8, the upperdisconnector 41 and the lower disconnector 40 are mainly shown, whilethe circuit breaker 1, the operating device 2, and the supporting base36 are omitted from the drawing.

The circuit breakers 1 included in the partial units (I), (II), and(III) are positioned so as to be parallel to one another, while thebranch outlets 3 and 7 of the circuit breakers 1 are all oriented in thesame direction. In other words, the partial units (I), (II), and (III)are arranged in a direction that is orthogonal to the branchingdirection of the branch outlets 3 and 7, i.e., a direction that isorthogonal to the circuit breaker 1 and the current transformers 4 and8. Further, as explained above, the height-direction positions of thecircuit breakers 1 are configured so as to become higher sequentiallyfrom the partial unit (I) to the partial unit (III). In FIGS. 8 and 9,two integral units each of which includes the partial units (I), (II),and (III) that are configured as described above are arranged side byside.

The upper main bus 11 is connected to the disconnector positioned in theuppermost level in each of the integral units (i.e., the disconnectors41 included in the partial units (III)) at the same height level. Thedisconnectors 41 included in the partial units (III) are thedisconnectors that are not connected to the upper disconnectors 41included in the partial units (II). Further, the lower main bus 12 isconnected to the disconnector positioned in the lowermost level in eachof the integral units (i.e., the disconnectors 40 included in thepartial units (I)) at the same height level. The disconnectors 40included in the partial units (I) are the disconnectors that are notconnected to the lower disconnectors 40 included in the partial units(II). As explained above, each of the disconnectors 41 included in thepartial units (III) has the upper main bus 11 integrally and linearlyconnected thereto while using a connection mode in which a T-shapedbranch structure is formed with respect to the connection direction inwhich the disconnector 41 is connected to the current transformer 8. Asa result, it is possible to arrange the upper main bus 11 linearlythroughout the plurality of integral units. The same applies to thelower main bus 12. In other words, each of the disconnectors 40 includedin the partial units (I) has the lower main bus 12 integrally andlinearly connected thereto while using a connection mode in which aT-shaped branch structure is formed with respect to the connectiondirection in which the disconnector 40 is connected to the currenttransformer 4. As a result, it is possible to arrange the lower main bus12 linearly throughout the plurality of integral units.

With regard to the partial unit (I), the line-side devices are providedso as to oppose the circuit breaker 1 while the disconnectors 40 and 41are interposed therebetween. The same positional arrangement alsoapplies to the partial unit (II). Accordingly, due to the 1½-CB-typeconfiguration, no line-side devices are provided for the partial unit(III). As described here, one set of line-side devices is connected toeach of the disconnectors included in two of the partial units (I),(II), and (III) while opposing the current-transformer-side connectionface. Further, throughout the plurality of integral units, the partialunits to which no line-side devices are connected are arranged atregular intervals in the direction in which the partial units arearranged. For example, in the example shown in FIG. 9, no line-sidedevices are connected to the partial units (III) in both of the twointegral units.

As explained above, the interval between the disconnectors connected toeach of the circuit breakers 1 included in the partial units (I), (II),and (III) is configured so as to be H, while the height-directionpositions of the circuit breakers 1 are configured so as to sequentiallybecome higher by H from the partial unit (I) to the partial unit (III).Further, the interval between the upper main bus 11 and the lower mainbus 12 is configured so as to be 3H, while each of the disconnectors 40included in the partial units (I) is connected to the lower main bus 12,whereas each of the disconnectors 41 included in the partial units (III)is connected to the upper main bus 11. This configuration is desirablefrom the aspect of standardizing the circuit breaker modules.

In the example shown in FIGS. 8 and 9, the partial units are arranged inthe following order from the left-hand side to the right-hand side ofthe drawings: the partial unit (I), the partial unit (II), and thepartial unit (III); however, needless to say, it is possible to arrangethe partial units in the reverse order.

According to the second embodiment, with regard to the plurality ofintegral units each of which includes the partial units (I), (II), and(III), the two branch outlets 3 and 7 of the circuit breakers 1 includedin the partial units are all oriented in the same direction while thepartial units are linearly arranged in the direction that is orthogonalto the orientation direction. Further, the line-side devices areprovided so as to oppose the circuit breakers 1 while the disconnectors40 and 41 are interposed therebetween. Thus, the devices are gathered onthe front and the rear faces of the partial units. In other words, thecircuit breakers 1 are principally positioned on the front face side ofthe partial units, whereas the line-side devices are principallypositioned on the rear face side of the partial units. As a result, itis possible to easily reach the devices including these elements, andthe configuration naturally makes it possible to secure the space thatis required by the maintenance and inspection processes. For example, inFIG. 9, there is no need to particularly provide the space used forperforming maintenance and inspection processes on the circuit breaker 1and the earth switches 16 and 27. It is possible to easily reach theoperating devices for operating these devices. As explained here,according to the second embodiment, because the devices are gathered onthe front and the rear faces of the partial units, there is no need toprovide another space used for performing the maintenance and inspectionprocesses on the devices. Thus, it is possible to reduce theinstallation space.

In addition, according to the second embodiment, because the partialunits are arranged side by side, it is possible to reduce the dimensionbetween the partial units and the dimension in the lengthwise directionof the partial units. As a result, it is possible to integrate thelayout of the entire electricity supply station in which the gasinsulated switchgear is installed. An advantageous effect is thereforeachieved where it is possible to save space easily. This arrangement iseffective especially when cable connections are used on the line side.Further, because the circuit breakers 1 are of the vertical type, theinstallation space in the electricity supply station does not increaseeven if the circuit breakers 1 are arranged, like in the secondembodiment, in such a manner that the heights thereof are different fromone another in the axial direction of thereof. It should be noted,however, that, in the case where the gas insulated switchgear isinstalled within a building, this arrangement is possible when theheight of the building has no limitation.

Further, according to the second embodiment, the vertical-type circuitbreakers 1 each having the two branch outlets 3 and 7 that are providedwhile arranging one above the other with an interval therebetween areused, so that a current transformer and a disconnector are connected inseries to each of the two branch outlets. Because of such a structure ofeach of the circuit breakers 1, there is no need to provide, on theinside of each of the circuit breakers 1, a folded structure ofconductors or the like, and it is therefore possible to simplify thestructure used for guiding the conductors. Thus, it is possible toreduce the diameter of the circuit breakers. As a result, it is possibleto shorten the intervals between the units and to further reduce theinstallation space.

Further, according to the second embodiment, each of the disconnectors40 and 41 has the T-shaped branch structure. As a result, it is possibleto reduce the number of tanks and spacers used for connecting thedevices to one another. Thus, it is possible not only to reduce theinstallation space, but also to reduce the costs. Furthermore, it ispossible to arrange the upper main bus 11 and the lower main bus 12linearly and to minimize the lengths of the upper main bus 11 and thelower main bus 12. In addition, by using the T-shaped branch structuresof the disconnectors 40 and 41, it is possible to provide additionalintegral units easily.

Furthermore, according to the second embodiment, one set of line-sidedevices is connected to each of the partial units. As a result, it ispossible to reduce the dimension in the lengthwise direction of thepartial units. Thus, it is possible to shorten the total length of theentire electricity supply station. Alternatively, another arrangement isalso acceptable in which, for example, two sets of line-side devices areconnected to one partial unit. As yet another arrangement, it is alsoacceptable to position the line-side devices between the partial units,by folding the structure back to the circuit breaker 1 side. Thisarrangement is suitable in a situation where the size of the line-sidedevices is large.

According to the second embodiment, one set of line-side devices isconnected to each of two of the partial units (I), (II), and (III).Further, throughout the plurality of integral units, the partial unitsto which no line-side devices are connected are arranged at regularintervals in the direction in which the partial units are arranged. Forexample, in the example shown in FIG. 2, no line-side devices areconnected to the partial units (III) in both of the two integral units.With this arrangement, because no line-side devices are connected to thepartial units (III), an empty space is formed in the lengthwisedirection of each of the partial units (III). By utilizing these emptyspaces (e.g., by providing, in an integrated manner, an operation boxthat also functions for the adjacent partial units), it is possible toeasily perform the maintenance and inspection processes not only on thedisconnectors 40 and 41 included in the partial unit (III), but also onthe disconnectors 40 and 41 included in the adjacent partial unit (I)and the disconnectors 40 and 41 included in the adjacent partial unit(II) on the opposite side. If such empty spaces were not positioned atregular intervals in the direction in which the partial units arearranged, there would be some disconnectors that are difficult to reach,and the convenience during the maintenance and inspection processeswould be hampered. As explained here, because the partial units (I),(II), and (III) and the line-side devices are arranged with highdensity, there is no need to provide a space dedicated to themaintenance and inspection processes. Thus, it is possible to shorten,in particular, the intervals between the partial units.

Further, according to the second embodiment, the interval between thedisconnectors connected to each of the circuit breakers 1 included inthe partial units (I), (II), and (III) is configured so as to be H,whereas the interval between the upper main bus 11 and the lower mainbus 12 is configured so as to be 3H. As a result, all the circuitbreakers 1 that are used can be the same as one another. Consequently,it is possible to standardize the circuit breaker modules regarding theconfigurations of the buses. This arrangement contributes to integrationof the positional arrangements and to cost reductions.

According to the second embodiment, for example, the path that extendsfrom the disconnector 41 to the cable head 24 changes direction by 90degrees at the line-side disconnector 25, so that the path substantiallyforms an L shape. As a result, it is possible to reduce the dimension inthe lengthwise direction of the partial units and to shorten the totallength of the electricity supply station.

In addition, according to the second embodiment, throughout theplurality of integral units, all the partial units are arranged at theregular intervals. As a result, it is possible to reduce the dimensionbetween the units and to shorten the width of the electricity supplystation.

In the sections above, the example of a three-phase system has beenexplained; however, the present invention is not limited to thisexample. It is possible to apply the present invention likewise to anisolated phase system.

Third Embodiment

FIG. 13 is a front view of an example of a positional arrangement of1½-CB-type gas insulated switchgear according to a third embodiment ofthe present invention. FIG. 14 is a top view corresponding to FIG. 13.FIG. 15 is a cross-sectional view of a device configuration including apartial unit (I) included in the gas insulated switchgear according tothe third embodiment and is a cross-sectional view at the line A-A inFIG. 13. FIG. 16 is a cross-sectional view of a device configurationincluding a partial unit (II) included in the gas insulated switchgearaccording to the third embodiment and is a cross-sectional view at theline B-B in FIG. 13. FIG. 17 is a cross-sectional view of a deviceconfiguration including a partial unit (III) included in the gasinsulated switchgear according to the third embodiment and is across-sectional view at the line C-C in FIG. 13.

The 1½-CB-type gas insulated switchgear according to the thirdembodiment is configured so as to include a plurality of integral units.Each of the integral units is structured by connecting partial units(I), (II), and (III) together in series, while line-side devices areconfigured so as to branch from a connection line that connects thepartial units (I) and (II) together and from a connection line thatconnects the partial units (II) and (III) together. Each of the partialunits (I), (II), and (III) is structured by connecting a currenttransformer and a disconnector with an earth switch in sequence to acircuit breaker on each of the two sides thereof. With regard to twomain buses, one end of each of the integral units is connected to one oftwo main buses, whereas the other end of each of the integral units isconnected to the other of the two main buses. Because the single-linewiring diagram according to the third embodiment is the same as the oneshown in FIG. 7, the explanation thereof will be omitted.

Next, configurations of the devices including the configurations of thepartial units (I), (II), and (III) will be explained in detail, withreference to FIGS. 15 to 17. After that, an overall layout will beexplained, with reference to FIGS. 13 and 14.

First, a configuration of the devices including the partial unit (I)will be explained. As shown in FIG. 10, a circuit breaker 51 that has acircular cylindrical shape and has an operating device 52 therefor ontop is provided so as to stand in such a manner that the axial linethereof extends perpendicular to the installation surface 100. In otherwords, the circuit breaker 51 is a vertical-type circuit breaker. Acircuit breaking unit (not shown) is provided on the inside of thecircuit breaker 51, which is a space filled with insulating and arcextinguishing gas such as SF₆.

On a lateral face of the circuit breaker 51, two branch outlets areprovided while having an up-and-down-direction interval 2H therebetween,the two branch outlets namely being a branch outlet 53 provided in alower position and a branch outlet 54 provided in an upper position. Thebranch outlets 53 and 54 are horizontally drawn out so as to branch fromthe lateral face of the circuit breaker 51 in the same direction.

A current transformer 55 and a disconnector 56 with an earth switch areconnected to the branch outlet 53 in series in the stated order. Anoperating device 58 for operating the disconnector 56 is provided on topof the disconnector 56. A lower main bus 64, which is the lower one oftwo main buses that extend along each other while arranged one above theother with interval therebetween, is connected to the disconnector 56via a connection terminal 57 provided for the disconnector 56.

A current transformer 59 and a disconnector 60 with an earth switch areconnected to the branch outlet 54 in series in the stated order. Aconnection bus 61 extending in a direction that is orthogonal to thecircuit breaker 51 and the current transformers 55 and 59 is connectedto the disconnector 60. The connection bus 61 connects together thepartial unit (I) and the partial unit (II) positioned adjacent to thepartial unit (I). An operating device 62 for operating the disconnector60 is provided on top of the disconnector 60.

An upper main bus 63, which is the upper one of the two main busesdescribed above, is provided in a position in the middle of thedisconnector 60 and the disconnector 56. In other words, the center ofthe cross section of the upper main bus 63 is positioned at the middlepoint of the straight line that connects the disconnector 60 and thedisconnector 56 together. Accordingly, the distance H between the uppermain bus 63 and the lower main bus 64 is a half of the distance 2Hbetween the disconnector 60 and the disconnector 56. The upper main bus63 and the lower main bus 64 are provided so as to extend horizontallyand parallel to each other. The direction in which the upper main busand the lower main bus extend is the same as the direction in which theconnection bus 61 extends.

Opposing the circuit breaker 51 while the disconnectors 56 and 60 areinterposed therebetween, cable head 66 is provided on a supporting base65, a line-side disconnector 67 with an earth switch is connected on topof the cable head 66, an operating device 97 for the line-sidedisconnector 67 is provided on a lateral face of the line-sidedisconnector 67, and a voltage transformer 68 is provided on top of theline-side disconnector 67. Also, while being connected to the line-sidedisconnector 67, an earth switch 69 for a line-side earth is provided onanother lateral face of the line-side disconnector 67 that is positionedon the opposite side from the circuit breaker 51. In addition, anoperating device 70 for operating the earth switch 69 is provided.Further, the line-side disconnector 67 is connected to the disconnector60, which is connected to the circuit breaker 51. The portion of thedisconnector 60 connected to the disconnector 67 is positioned on theopposite side from the current transformer 59 so as to oppose theconnection portion at which the disconnector 60 is connected to thecurrent transformer 59. In other words, the disconnector 60 has aT-shaped branch structure in which a branch portion to which the currenttransformer 59 is connected and another branch portion to which theline-side disconnector 67 is connected are positioned so as to opposeeach other, while the connection bus 61 is connected to the other branchportion that is orthogonal to these opposing branches. As explainedhere, the disconnector 60 branches in the shape of a T on a horizontalplane, which is positioned parallel to the installation surface 100.

A path that extends from the disconnector 60 to the cable head 66changes direction by 90 degrees at the line-side disconnector 67, sothat the path substantially forms an L shape.

As explained above, the partial unit (I) includes the vertical-typecircuit breaker 51 provided with the branch outlets 53 and 54, thecurrent transformers 55 and 59, and the disconnectors 56 and 60 eachprovided with an earth switch. Further, the line-side devices such asthe cable head 66, the line-side disconnector 67, and the voltagetransformer 68 are connected so as to oppose the circuit breaker 51while the disconnectors 56 and 60 are interposed therebetween.

Next, configurations of the devices including the partial unit (II) willbe explained. Some of the constituent elements that are the same asthose in the partial unit (I) will be referred to by using the samereference characters. As shown in FIG. 16, a circuit breaker 71 that hasa circular cylindrical shape is provided on a supporting base 73, whilean operating device 72 is interposed therebetween. The circuit breaker71 is a vertical-type circuit breaker that is provided so as to stand insuch a manner that the axial line thereof extends perpendicular to theinstallation surface 100.

On a lateral face of the circuit breaker 71, two branch outlets areprovided while having an up-and-down-direction interval H therebetween,the two branch outlets namely being a branch outlet 74 provided in alower position and a branch outlet 75 provided in an upper position. Thebranch outlets 74 and 75 are horizontally drawn out so as to branch fromthe lateral face of the circuit breaker 71 in the same direction.

A current transformer 76 and a disconnector 77 with an earth switch areconnected to the branch outlet 74 in series in the stated order. Anoperating device 78 for operating the disconnector 77 is provided on topof the disconnector 77.

A current transformer 79 and a disconnector 80 with an earth switch areconnected to the branch outlet 75 in series in the stated order. Anoperating device 82 for operating the disconnector 80 is provided on topof the disconnector 80.

A connection bus 81 extending in a direction that is orthogonal to thecircuit breaker 71 and the current transformers 76 and 79 is connectedto the disconnector 80. The connection bus 81 connects together thepartial unit (II) and the partial unit (III), which is positionedadjacent to the partial unit (II). The connection bus 61 extending in adirection that is orthogonal to the circuit breaker 71 and the currenttransformers 76 and 79 is connected to the disconnector 77. As explainedabove, the connection bus 61 connects the partial unit (II) and thepartial unit (I) together. The connection bus 81 extends in a directionopposite from the direction in which the connection bus 61 extends.

Below the disconnector 77, the lower main bus 64 and the upper main bus63 are provided so as to be stacked in the manner of layers, whilehaving a interval H therebetween. Further, the disconnector 77 ispositioned higher than the upper main bus 63 by the distance H. In otherwords, the lower main bus 64, the upper main bus 63, the disconnector77, and the disconnector 80 are provided in the stated order from alower position to an upper position, while having an interval Htherebetween. The connection buses 81 and 61 extend parallel to theupper main bus 63 and the lower main bus 64.

Opposing the circuit breaker 71 while the disconnectors 77 and 80 eachprovided with an earth switch are interposed therebetween, a cable head84 is provided on a supporting base 83, a line-side disconnector 85 withan earth switch is connected on top of the cable head 84, an operatingdevice 89 for the line-side disconnector 85 is provided on a lateralface of the line-side disconnector 85, and a voltage transformer 86 isprovided on top of the line-side disconnector 85. Also, while beingconnected to the line-side disconnector 85, an earth switch 87 for aline-side earth is provided on another lateral face of the line-sidedisconnector 85 that is positioned on-the opposite side from the circuitbreaker 71. In addition, an operating device 88 for operating the earthswitch 87 is provided. Further, the line-side disconnector 85 isconnected to the disconnector 80, which is connected to the circuitbreaker 71. The portion of the disconnector 80 connected to thedisconnector 85 is positioned on the opposite side from the currenttransformer 79 so as to oppose the connection portion at which thedisconnector 80 is connected to the current transformer 79. In otherwords, the disconnector 80 has a T-shaped branch structure in which abranch portion to which the current transformer 79 is connected andanother branch portion to which the line-side disconnector 85 isconnected are positioned so as to oppose each other, while theconnection bus 81 is connected to the other branch portion that isorthogonal to these opposing branches. As explained here, thedisconnector 80 branches in the shape of a T on a horizontal plane thatis positioned parallel to the installation surface 100.

A path that extends from the disconnector 80 to the cable head 84changes direction by 90 degrees at the line-side disconnector 85, sothat the path substantially forms an L shape.

As explained above, the partial unit (II) includes the vertical-typecircuit breaker 71 provided with the branch outlets 74 and 75, thecurrent transformers 76 and 79, and the disconnectors 77 and 80 eachprovided with an earth switch. Further, the line-side devices such asthe cable head 84, the line-side disconnector 85, and the voltagetransformer 86 are connected so as to oppose the circuit breaker 71while the disconnectors 77 and 80 are interposed therebetween.

Next, configurations of the devices including the partial unit (III)will be explained. Some of the constituent elements that are the same asthose in the partial units (I) and (II) will be referred to by using thesame reference characters. As shown in FIG. 17, a vertical-type circuitbreaker 51 is provided while an operating device 92 for operating thecircuit breaker 51 is provided underneath the circuit breaker 51. Likein the partial unit (I), the branch outlets 53 and 54 are provided on alateral face of the circuit breaker 51. The current transformer 55 andthe disconnector 56 with an earth switch are connected in series to thebranch outlet 53 in sequence, whereas the current transformer 59 and thedisconnector 60 with an earth switch are connected in series to thebranch outlet 54 in sequence.

The operating device 58 for operating the disconnector 56 is provided ontop of the disconnector 56. Further, the upper main bus 63 is connectedto the disconnector 56 via a connection terminal 98 provided for thedisconnector 56, while extending in a direction that is orthogonal tothe circuit breaker 51 and the current transformers 55 and 59. The lowermain bus 64 is positioned below the upper main bus 63 while having thedistance H therebetween.

The operating device 62 for operating the disconnector 60 is provided ontop of the disconnector 60. Further, the connection bus 81 connectingthe partial unit (III) and the partial unit (II) together is connectedto the disconnector 60. The interval between the disconnector 60 and thedisconnector 56 can be expressed as a distance 2H. It should be notedthat no line-side devices are provided so as to oppose the partial unit(III).

Next, a layout according to the third embodiment will be explained indetail, with reference to FIGS. 13 and 14. As shown in FIGS. 13 and 14,in the 1½-CB-type gas insulated switchgear according to the thirdembodiment, for example, two integral units are arranged side by side.Each of the integral units includes the partial unit (I), the partialunit (II), and the partial unit (III). Further, throughout both of thetwo integral units, the intervals between two partial units areconfigured so as to be regular intervals each of which can be expressedas W.

Next, a positional relationship between the partial unit (I) and thepartial unit (II) will be explained. The lower disconnector 56 includedin the partial unit (I) is connected to the lower main bus 64. Thedistance between the upper disconnector 60 and the lower disconnector 56included in the partial unit (I) is configured so as to be 2H, which islonger than the distance H between the upper main bus 63 and the lowermain bus 64, which are positioned in the lower layers. As a result, theupper disconnector 60 included in the partial unit (I) is positionedabove the upper main bus 63. Further, the height of the supporting base83 is adjusted in such a manner that the height of the lowerdisconnector 77 included in the partial unit (II) is equal to the heightof the upper disconnector 60 included in the partial unit (I). Inaddition, the disconnector 60 included in the partial unit (I) and thedisconnector 77 included in the partial unit (II) are connected to eachother at the same height level by the connection bus 61.

Next, a positional relationship between the partial unit (II) and thepartial unit (III) will be explained. The upper disconnector 80 includedin the partial unit (II) is positioned higher than the lowerdisconnector 77 by the distance H. Further, the lower disconnector 56included in the partial unit (III) is connected to the upper main bus63, whereas the upper disconnector 60 included in the partial unit (III)is positioned higher than the lower disconnector 56 by the distance 2H.As a result, the height of the upper disconnector 80 included in thepartial unit (II) is equal to the height of the upper disconnector 60included in the partial unit (III). Thus, the disconnector 80 includedin the partial unit (II) and the disconnector 60 included in the partialunit (III) are connected to each other at the same height level by theconnection bus 81. To clearly indicate the relative positionalrelationships among the partial units, in the drawing of the partialunit (III) in FIG. 13, the upper disconnector 60 and the lowerdisconnector 56 are mainly shown, while the circuit breaker 51 and theoperating device 92 are omitted from the drawing.

As apparent in FIG. 14, the circuit breaker 51 included in the partialunit (I), the circuit breaker 71 included in the partial unit (II), andthe circuit breaker 51 included in the partial unit (III) are positionedso as to be parallel to one another, while the branch outlets thereofare oriented in the same direction, whereas the circuit breakers arearranged in a direction that is orthogonal to the orientation direction.In FIGS. 13 and 14, two integral units each of which includes thepartial units (I), (II), and (III) that are configured as describedabove are arranged side by side.

With regard to the partial unit (I), the line-side devices are providedso as to oppose the circuit breaker 51 while the disconnectors 56 and 60are interposed therebetween. The same positional arrangement alsoapplies to the partial unit (II). Accordingly, due to the 1½-CB-typeconfiguration, no line-side devices are provided for the partial unit(III). As described here, one set of line-side devices is connected toeach of the disconnectors included in two of the partial units (I),(II), and (III), on a lateral face that opposes thecurrent-transformer-side connection face. Further, throughout theplurality of integral units, the partial units to which no line-sidedevices are connected are arranged at regular intervals in the directionin which the partial units are arranged. For example, in the exampleshown in FIG. 14, no line-side devices are connected to the partialunits (III) in both of the two integral units.

As explained above, the axial length of the circuit breaker 51 includedin the partial unit (I) is configured so as to be longer than the axiallength of the circuit breaker 71 included in the partial unit (II), sothat the connection between the disconnector 60 included in the partialunit (I) and the disconnector 77 included in the partial unit (II) ismade above the upper main bus 63. Further, the interval between thedisconnectors connected to the circuit breaker 51 included in thepartial unit (I) is configured so as to be 2H, whereas the intervalbetween the disconnectors connected to the circuit breaker 71 includedin the partial unit (II) is configured so as to be H, while the intervalbetween the disconnectors connected to the circuit breaker 51 includedin the partial unit (III) is configured so as to be 2H, and the intervalbetween the upper main bus 63 and the lower main bus 64 is configured soas to be H. This configuration is desirable from the aspect ofstandardizing the circuit breaker modules.

In the example shown in FIGS. 13 and 14, the partial units are arrangedin the following order from the left-hand side to the right-hand side ofthe drawings: the partial unit (I), the partial unit (II), and thepartial unit (III); however, needless to say, it is possible to arrangethe partial units in the reverse order. In addition, to obtain theconnection mode in which the lower disconnector 56 included in thepartial unit (I) is connected to the lower main bus 64, while theconnection between the partial unit (I) and the partial unit (II) ismade above the upper main bus 63, whereas the lower disconnector 56included in the partial unit (III) is connected to the upper main bus63, the connection mode is not limited to the example shown in FIGS. 13and 14. It is acceptable to adopt other connection modes. For example,another arrangement is acceptable in which the upper disconnector 60included in the partial unit (I) is connected to the upper disconnector80 included in the partial unit (II), whereas the lower disconnector 77included in the partial unit (II) is connected to the upper disconnector60 included in the partial unit (III). In this situation, however, someadjustments as follows, for example, need to be made: the axial lengthof the circuit breaker 51 included in the partial unit (I) is configuredso as to be longer, so that the interval between the disconnectorsbecomes longer as necessary; the position of the circuit breaker 71included in the partial unit (II) is configured so as to be higher,while the axial length of the circuit breaker 71 is configured so as tobe longer, so that the interval between the disconnectors becomes longeras necessary; and the axial length of the circuit breaker 51 included inthe partial unit (III) is configured so as to be shorter, so that theinterval between the disconnectors becomes shorter as necessary. In thissituation also, the axial length of the circuit breaker 51 included inthe partial unit (I) is longer than the axial length of the circuitbreaker 71 included in the partial unit (II).

According to the third embodiment, with regard to the plurality ofintegral units each of which includes the partial units (I), (II), and(III), the two branch outlets of the circuit breakers included in thepartial units are all oriented in the same direction, while the partialunits are linearly arranged in the direction that is orthogonal to theorientation direction. Further, the line-side devices are provided so asto oppose the circuit breakers while the disconnectors are interposedtherebetween. Thus, the devices are gathered on the front and the rearfaces of the partial units. In other words, the circuit breakers areprincipally positioned on the front face side of the partial units,whereas the line-side devices are principally positioned on the rearface side of the partial units. As a result, it is possible to easilyreach the devices including these elements, and the configurationnaturally makes it possible to secure the space that is required by themaintenance and inspection processes. For example, in FIG. 14, there isno need to particularly provide a space dedicated to perform maintenanceand inspection processes on the circuit breaker 51 and the earthswitches 69 and 87. It is possible to easily reach the operating devicesfor operating these devices. As explained here, according to the thirdembodiment, because the devices are gathered on the front and the rearfaces of the partial units, there is no need to separately provideanother space used for performing the maintenance and inspectionprocesses on the devices. Thus, it is possible to reduce theinstallation space.

In addition, according to the third embodiment, because the partialunits are arranged side by side, it is possible to reduce the dimensionbetween the partial units and the dimension in the lengthwise directionof the partial units. As a result, it is possible to integrate thelayout of the entire electricity supply station in which the gasinsulated switchgear is installed. An advantageous effect is thereforeachieved where it is possible to save space easily. This arrangement iseffective especially when cable connections are used on the line side.Further, because the circuit breakers 51 and 71 are of the verticaltype, the installation space in the electricity supply station does notincrease even if the circuit breakers 51 and 71 are arranged, like inthe third embodiment, in such a manner that the heights thereof aredifferent from one another in the axial direction of thereof. It shouldbe noted, however, that, in the case where the gas insulated switchgearis installed within a building, this arrangement is possible when theheight of the building has no limitation.

Further, according to the third embodiment, the vertical-type circuitbreakers 51 and 71 each having the two branch outlets 3 and 7 that areprovided while having the up-and-down direction interval therebetweenare used, so that a current transformer and a disconnector are connectedin series to each of the two branch outlets. Because of such a structureof each of the circuit breakers 51 and 71, there is no need to provide,on the inside of each of the circuit breakers 51 and 71, a foldedstructure of conductors or the like, and it is therefore possible tosimplify the structure used for guiding the conductors. Thus, it ispossible to reduce the diameter of the circuit breakers. As a result, itis possible to shorten the intervals between the units and to furtherreduce the installation space.

Further, according to the third embodiment, each of the disconnectors 56and 60 has the T-shaped branch structure. As a result, it is possible toreduce the number of tanks and spacers used for connecting the devicesto one another. Thus, it is possible not only to reduce the installationspace, but also to reduce the costs. Furthermore, it is possible toarrange the upper main bus 63 and the lower main bus 64 linearly and tominimize the lengths of the upper main bus 63 and the lower main bus 64.In addition, by using the T-shaped branch structures of thedisconnectors 56 and 60, it is possible to provide additional integralunits easily.

Furthermore, according to the third embodiment, one set of line-sidedevices is connected to each of the partial units. As a result, it ispossible to reduce the dimension in the lengthwise direction of thepartial units. Thus, it is possible to shorten the total length of theentire electricity supply station. Alternatively, another arrangement isalso acceptable in which, for example, two sets of line-side devices areconnected to one partial unit. As yet another arrangement, it is alsoacceptable to position the line-side devices between the partial units,by folding the structure back to the circuit breaker 1 side. Thisarrangement is suitable in a situation where the size of the line-sidedevices is large.

According to the third embodiment, one set of line-side devices isconnected to each of two of the partial units (I), (II), and (III).Further, throughout the plurality of integral units, the partial unitsto which no line-side devices are connected are arranged at regularintervals in the direction in which the partial units are arranged. Forexample, in the example shown in FIG. 14, no line-side devices areconnected to the partial units (III) in both of the two integral units.With this arrangement, because no line-side devices are connected to thepartial units (III), an empty space is formed in the lengthwisedirection of each of the partial units (III). By utilizing these emptyspaces (e.g., by providing, in an integrated manner, an operation boxthat also functions for the adjacent partial units), it is possible toeasily perform the maintenance and inspection processes not only on thedisconnectors 60 and 56 included in the partial unit (III), but also onthe disconnectors 60 and 56 included in the adjacent partial unit (I)and the disconnectors 80 and 77 included in the adjacent partial unit(II) on the opposite side. If such empty spaces were not positioned atregular intervals in the direction in which the partial units arearranged, there would be some disconnectors that are difficult to reach,and the convenience during the maintenance and inspection processeswould be hampered. As explained here, because the partial units (I),(II), and (III) and the line-side devices are arranged with highdensity, there is no need to provide a space dedicated to themaintenance and inspection processes. Thus, it is possible to shorten,in particular, the intervals between the partial units.

According to the third embodiment, because the upper main bus 63 and thelower main bus 64 are positioned in the lower layers, quake-resistanceproperties are improved.

Further, according to the third embodiment, the interval between thedisconnectors connected to the circuit breaker 51 included in thepartial units (I) is configured so as to be 2H, whereas the intervalbetween the disconnectors connected to the circuit breaker 71 includedin the partial unit (II) is configured so as to be H, while the intervalbetween the disconnectors connected to the circuit breaker 51 includedin the partial unit (III) is configured so as to be 2H, and the intervalbetween the upper main bus 63 and the lower main bus 64 is configured soas to be H. As a result, it is possible to standardize the circuitbreaker modules including the configurations of the buses. Thisarrangement contributes to integration of the positional arrangementsand to cost reductions.

According to the third embodiment, for example, the path that extendsfrom the disconnector 60 to the cable head 66 changes direction by 90degrees at the line-side disconnector 67, so that the path substantiallyforms an L shape. As a result, it is possible to reduce the dimension inthe lengthwise direction of the partial units and to shorten the totallength of the electricity supply station.

In addition, according to the third embodiment, throughout the pluralityof integral units, all the partial units are arranged at the regularintervals. As a result, it is possible to reduce the dimension betweenthe units and to shorten the width of the electricity supply station.

In the sections above, the example of a three-phase system has beenexplained; however, the present invention is not limited to thisexample. It is possible to apply the present invention likewise to anisolated phase system.

INDUSTRIAL APPLICABILITY

As explained above, the gas insulated switchgear according to an aspectof the present invention is suitable for reducing the installation spacein electricity supply stations such as substations and electric powerplants.

1. Gas insulated switchgear including a plurality of integral units, ineach of which a first partial unit, a second partial unit, and a thirdpartial unit are connected in series in sequence while line-side devicesare branched from a position between the first partial unit and thesecond partial unit and from a position between the second partial unitand the third partial unit, each of the first, the second, and the thirdpartial units including: a circuit breaker of a vertical type having twobranch outlets formed of upper and lower branch outlets thathorizontally branch from a lateral face of the circuit breaker in a samedirection; a current transformer and an upper disconnector that areconnected in sequence to the upper branch outlet; and another currenttransformer and a lower disconnector that are connected in sequence tothe lower branch outlet, one end of each of the integral units beingconnected to an upper main bus, whereas other end of each of theintegral units being connected to a lower main bus, the upper and lowermain buses being provided in an upper position and a lower position,respectively, wherein the first, the second, and the third partial unitsare arranged in an arranged direction side by side such that heights ofthe circuit breakers are equal to one another and that the two branchoutlets therein are oriented in a same direction, the lower disconnectorincluded in the second partial unit and the lower disconnector includedin the first or the third partial unit are at a same height and areconnected by a connection bus, whereas the upper disconnector includedin the second partial unit and the upper disconnector included in thefirst or the third partial unit, which is not connected to the lowerdisconnector included in the second partial unit, are at a same heightand are connected by a connection bus, the upper and lower disconnectorsin each of the first, the second, and the third partial units areinterposed between the upper and lower main buses extending in thearranging direction, the upper disconnector included in the first or thethird partial unit that is connected to the lower disconnector includedin the second partial unit is connected to the upper main bus via aT-shaped branch structure provided on the upper main bus, and the lowerdisconnector included in the first or the third partial unit that isconnected to the upper disconnector included in the second partial unitis connected to the lower main bus via a T-shaped branch structureprovided on the lower main bus.
 2. The gas insulated switchgearaccording to claim 1, wherein the line-side devices are each connectedto the upper or the lower disconnector included in two of the first, thesecond, and the third partial units, on a lateral face of thedisconnector that opposes another lateral face on which a correspondingone of the current transformers is connected, and throughout theplurality of integral units, the partial units to which no line-sidedevices are connected, are arranged at regular intervals.
 3. The gasinsulated switchgear according to claim 2, wherein a path that extendsfrom the disconnector, to which any of the line-side devices isconnected, to the line-side device includes an L-shaped path.
 4. Gasinsulated switchgear including a plurality of integral units, in each ofwhich a first partial unit, a second partial unit, and a third partialunit are connected in series in sequence while line-side devices arebranched from a position between the first partial unit and the secondpartial unit and from a position between the second partial unit and thethird partial unit, each of the first, the second, and the third partialunits including: a circuit breaker of a vertical type having two branchoutlets formed of upper and lower branch outlets that horizontallybranch from a lateral face of the circuit breaker in a same direction; acurrent transformer and an upper disconnector that are connected insequence to the upper branch outlet; and another current transformer anda lower disconnector that are connected in sequence to the lower branchoutlet, one end of each of the integral units being connected to anupper main bus, whereas other end of each of the integral units beingconnected to a lower main bus, the upper and lower main buses beingprovided in an upper position and a lower position, respectively,wherein the first, the second, and the third partial units are linearlyarranged in an arranging direction that is orthogonal to an orientationdirection in which the two branch outlets of the first, second, andthird partial units are oriented, the upper main bus and the lower mainbus extend in the arranging direction, the lower disconnector includedin the second partial unit and the upper disconnector included in thefirst or the third partial unit are at a same height and are connectedby a connection bus, whereas the upper disconnector included in thesecond partial unit and the lower disconnector included in the first orthe third partial unit, which is not connected to the lower disconnectorincluded in the second partial unit, are at a same height and areconnected by a connection bus, the upper disconnector included in thefirst or the third partial unit, which is connected to the upperdisconnector included in the second partial unit, is connected to theupper main bus at a same height level, whereas the lower disconnectorincluded in the first or the third partial unit, which is connected tothe lower disconnector included in the second partial unit, is connectedto the lower main bus at a same height level, and the line-side devicesoppose the circuit breakers while interposing the upper main bus and thelower main bus therebetween.
 5. The gas insulated switchgear accordingto claim 4, wherein each of the disconnectors that are respectivelyconnected to the upper and lower main buses is configured to integrallyand lineally connect the main bus using a T-shaped branch structure inwhich the main bus branches in a form of T from a direction along whichthe disconnector is connected to a corresponding one of the currenttransformer.
 6. The gas insulated switchgear according to claim 4,wherein an interval between the upper disconnector and the lowerdisconnector is equal in all of the first, the second, and the thirdpartial units.
 7. The gas insulated switchgear according to claim 4,wherein the line-side devices are each connected to the upper or thelower disconnector, which is included in two of the first, the second,and the third partial units, on a lateral face of the disconnector thatopposes another lateral face on which a corresponding one of the currenttransformers is connected, and throughout the plurality of integralunits, the partial units to which no line-side devices are connected,are arranged at regular intervals.
 8. The gas insulated switchgearaccording to claim 7, wherein a path that extends from the disconnector,to which any of the line-side devices is connected, to the line-sidedevice includes an L-shaped path.
 9. Gas insulated switchgear includinga plurality of integral units, in each of which a first partial unit, asecond partial unit, and a third partial unit are connected in series insequence while line-side devices are branched from a position betweenthe first partial unit and the second partial unit and from a positionbetween the second partial unit and the third partial unit, each of thefirst, the second, and the third partial units including: a circuitbreaker of a vertical type having two branch outlets formed of upper andlower branch outlets that horizontally branch from a lateral face of thecircuit breaker in a same direction; a current transformer and an upperdisconnector that are connected in sequence to the upper branch outlet;and another current transformer and a lower disconnector that areconnected in sequence to the lower branch outlet, one end of each of theintegral units being connected to an upper main bus, whereas other endof each of the integral units being connected to a lower main bus, theupper and lower main buses being provided in an upper position and alower position, respectively, wherein the first, the second, and thethird partial units are linearly arranged in an arranging direction thatis orthogonal to an orientation direction in which the two branchoutlets of the first, the second, and the third partial units areoriented, the upper main bus and the lower main bus extend in thearranging direction, the lower disconnector included in the first or thethird partial unit is connected to the upper main bus at a same heightlevel, whereas the lower disconnector included in the first or the thirdpartial unit that is not connected to the upper main bus is connected tothe lower main bus at a same height level, and the line-side devices areprovided so as to oppose the circuit breakers while interposing theupper main bus and the lower main bus therebetween.
 10. The gasinsulated switchgear according to claim 9, wherein an interval betweenthe upper disconnector and the lower disconnector that are connected tothe circuit breaker, which is included in at least one of the first andthe third partial units, is longer than an interval between the upperdisconnector and the lower disconnector that are connected to thecircuit breaker, which is included in the second partial unit, and oneof the two disconnectors included in the second partial unit isconnected to the upper disconnector included in the first partial unitin a position higher than the upper main bus, whereas other of the twodisconnectors included in the second partial unit is connected to theupper disconnector included in the third partial unit in a positionhigher than the upper main bus.
 11. The gas insulated switchgearaccording to claim 10, wherein the interval between the upperdisconnector and the lower disconnector included in the second partialunit is equal to an interval between the upper main bus and the lowermain bus, and an interval between the upper disconnector and the lowerdisconnector included in each of the first and the third partial unitsis twice as long as the interval between the upper main bus and thelower main bus.
 12. The gas insulated switchgear according to claim 9,wherein the line-side devices are each connected to the upper or thelower disconnector, which is included in two of the first, the second,and the third partial units, on a lateral face of the disconnector thatopposes another lateral face on which a corresponding one of the currenttransformers is connected, and throughout the plurality of integralunits, the partial units to which no line-side devices are connected,are arranged at regular intervals.
 13. The gas insulated switchgearaccording to claim 12, wherein a path that extends from thedisconnector, to which any of the line-side devices is connected, to theline-side device includes an L-shaped path.
 14. The gas insulatedswitchgear according to claim 1, wherein intervals between any two ofthe first, the second, and the third partial units that are positionedadjacent to each other are configured so as to be regular intervalsthroughout the plurality of integral units.
 15. The gas insulatedswitchgear according to claim 4, wherein intervals between any two ofthe first, the second, and the third partial units that are positionedadjacent to each other are configured so as to be regular intervalsthroughout the plurality of integral units.
 16. The gas insulatedswitchgear according to claim 9, wherein intervals between any two ofthe first, the second, and the third partial units that are positionedadjacent to each other are configured so as to be regular intervalsthroughout the plurality of integral units.